finished backend

backend/server.js

@@ -1,54 +1,198 @@
 import express from "express";
-
+import dotenv from "dotenv";
+import axios from "axios";
+import { formatData } from "./formatter.js";
+dotenv.config();
 const app = express();
 
-app.get("/api/today", (req, res) => {
-  const userLink = req.query.userLink;
+app.use(express.json());
 
-  // Simulate fetching today's schedule
-  const todaySchedule = {
-    subjects: [
-      {
-        lesson_nr: "1.",
-        name: "D G2",
-        room: "255",
-        teacher: "VanC",
-        clock: "08:00-08:55",
-        cancelled: false,
-      },
-      {
-        lesson_nr: "2. & 3.",
-        name: "M G2",
-        room: "255",
-        teacher: "ScLa",
-        clock: "08:55-10:25",
-        cancelled: false,
-      },
-      {
-        lesson_nr: "4.",
-        name: "E G4",
-        room: "254",
-        teacher: "RadF",
-        clock: "10:55-11:40",
-        cancelled: false,
-      },
-      {
-        lesson_nr: "5.",
-        name: "CH G2",
-        room: "133",
-        teacher: "LenT",
-        clock: "11:40-12:25",
-        cancelled: true,
-      },
-    ],
-    date: "15.04.2026",
-    day: "Mittwoch",
-    week: "16",
-    student: "Max Mustermann",
+app.get("/api/get-timetable/", async (req, res) => {
+  const username = req.query.username; // required
+  const password = req.query.password; // required
+  const school = req.query.school; // required
+
+  if (!username || !password || !school) {
+    res.status(400).json({
+      error: "Missing required query params: username, password, school",
+    });
+    return;
+  }
+
+  let startDate = req.query.startDate; // optional - expected format: YYYYMMDD
+  let endDate = req.query.endDate; // optional - expected format: YYYYMMDD
+
+  let sessionId = ""; // will be set after authentication by server response
+  let personId = ""; // will be set after authentication by server response
+  let personType = ""; // will be set after authentication by server response
+
+  // static function for checking or/and generating start and end date for the current week
+  function setDates() {
+    if (startDate && endDate) {
+      return;
+    }
+
+    const now = new Date();
+    const today = new Date(now.getFullYear(), now.getMonth(), now.getDate());
+    const dayOfWeek = today.getDay(); // 0 (Sunday) to 6 (Saturday)
+
+    const addDays = (date, days) =>
+      new Date(date.getFullYear(), date.getMonth(), date.getDate() + days);
+
+    // format dates to YYYYMMDD
+    const formatDate = (date) => {
+      const year = date.getFullYear();
+      const month = String(date.getMonth() + 1).padStart(2, "0");
+      const day = String(date.getDate()).padStart(2, "0");
+      return `${year}${month}${day}`;
+    };
+
+    // Desired behavior:
+    // - Weekday (Mon-Thu): startDate = today, endDate = coming Friday (same week)
+    // - Friday: startDate = today, endDate = coming Friday (next week)
+    // - Weekend (Sat/Sun): startDate = coming Monday, endDate = coming Friday (of that week)
+    const isWeekend = dayOfWeek === 0 || dayOfWeek === 6;
+
+    let start;
+    let end;
+
+    if (isWeekend) {
+      const daysUntilMonday = dayOfWeek === 0 ? 1 : 2; // Sun->Mon:1, Sat->Mon:2
+      start = addDays(today, daysUntilMonday);
+      end = addDays(start, 4); // Monday + 4 days = Friday
+    } else {
+      start = today;
+      const daysUntilFriday = 5 - dayOfWeek; // Mon(1)->4 ... Fri(5)->0
+      end = addDays(today, daysUntilFriday === 0 ? 7 : daysUntilFriday);
+    }
+
+    startDate = formatDate(start);
+    endDate = formatDate(end);
+  }
+
+  setDates();
+
+  const baseUrl = `https://${school}.webuntis.com/WebUntis/jsonrpc.do?school=${school}`;
+
+  const toJsonRpcError = (data) => {
+    const err = data?.error;
+    if (!err) return null;
+    const code = err.code;
+    const message = err.message || "Unknown WebUntis error";
+    return { code, message };
   };
 
-  console.log(`Fetching schedule for user: ${userLink}`);
-  res.json(todaySchedule);
+  try {
+    // 1) authenticate
+    const authResponse = await axios.post(baseUrl, {
+      id: "1",
+      method: "authenticate",
+      params: {
+        user: username,
+        password: password,
+        client: "watch-untis",
+      },
+      jsonrpc: "2.0",
+    });
+
+    const authErr = toJsonRpcError(authResponse.data);
+    if (authErr) {
+      if (authErr.message === "bad credentials") {
+        res.status(401).json({ error: "Invalid username or password" });
+        return;
+      }
+      if (authErr.code === -8504) {
+        res.status(403).json({ error: "WebUntis Error: -8504" });
+        return;
+      }
+      res.status(502).json({ error: authErr.message, code: authErr.code });
+      return;
+    }
+
+    sessionId = authResponse.data?.result?.sessionId;
+    personId = authResponse.data?.result?.personId;
+    personType = authResponse.data?.result?.personType;
+    if (!sessionId || !personId) {
+      res.status(502).json({
+        error: "WebUntis auth succeeded but returned no sessionId/personId",
+      });
+      return;
+    }
+
+    // 2) get timetable (after we have sessionId, personId & personType from auth response)
+    const timetableResponse = await axios.post(
+      baseUrl,
+      {
+        id: "3",
+        method: "getTimetable",
+        params: {
+          options: {
+            element: {
+              id: personId,
+              type: personType,
+            },
+            startDate,
+            endDate,
+            teacherFields: ["id", "name", "longname"],
+            subjectFields: ["id", "name", "longname"],
+            roomFields: ["id", "name", "longname"],
+          },
+        },
+        jsonrpc: "2.0",
+      },
+      {
+        headers: {
+          Cookie: `JSESSIONID=${sessionId}`,
+        },
+      },
+    );
+
+    const timetableErr = toJsonRpcError(timetableResponse.data);
+    if (timetableErr) {
+      res
+        .status(502)
+        .json({ error: timetableErr.message, code: timetableErr.code });
+      return;
+    }
+
+    // 3) format the data once it successfully returned
+    try {
+      const formattedData = formatData(timetableResponse.data);
+      res.json(formattedData);
+    } catch (formatError) {
+      console.error("formatData failed", formatError);
+      res.status(500).json({ error: "Failed to format timetable data" });
+    }
+
+    // respond to client
+    res.json(timetableResponse.data?.result ?? null);
+    return;
+  } catch (error) {
+    const status = error?.response?.status;
+    const data = error?.response?.data;
+    const jsonRpcErr = toJsonRpcError(data);
+
+    if (jsonRpcErr?.message === "bad credentials") {
+      res.status(401).json({ error: "Invalid username or password" });
+      return;
+    }
+    if (jsonRpcErr?.code === -8504) {
+      res.status(403).json({ error: "WebUntis Error: -8504" });
+      return;
+    }
+
+    console.error(error);
+    res.status(502).json({
+      error: "Failed to fetch timetable",
+      upstreamStatus: status,
+    });
+  }
+});
+
+// error handling code
+app.use((err, req, res, next) => {
+  console.error(err.stack);
+  res.status(500).send("Something broke!");
 });
 
 app.listen(8001, () => {